Eid-ul-Adha (Festival of the Sacrifice)

This takes place on the third day of hajj and it remembers the day that Abraham was going to sacrifice his son Isaac. It is celebrated like the other one but in this one they also sacrifices a lamb.

Ashura

Lands on the tenth day of the first month and it commemorates Moses exodus from Egypt for the Sunnis, and for the shi'as it commemorates the tragic death of the prophets grandson.

Hajj (Annual Pilgrimage to Mecca)l

This is when Muslims travel to the city of Mecca and do their annual rituals which is one part of the five pillars.